In electronics and electrical engineering a fuse (short for fusible link), is a type of overcurrent protection device, generally formed of a metal wire or strip that melts when too much current flows, which breaks the circuit in which it is connected, thus protecting the circuit's other components from damage due to excessive current.
A practical fuse was one of the features of Thomas Edison's electrical power distribution system. An early fuse was said to have successfully protected an Edison installation from tampering by a rival gas-lighting concern.
Fuses (and other overcurrent devices) are a part of a conventional power distribution system to prevent fire or damage. When too much current flows through a wire, it may overheat and be damaged or even start a fire. Wiring regulations give the maximum rating of a fuse for protection of a particular circuit. Local authorities incorporate national wiring regulations as part of law. Fuses are selected to allow passage of normal currents, but to quickly interrupt a short circuit or overload condition.
The use of the same reference symbols in different drawings indicates similar or identical items.